Bluetooth Based Home Automation
BLUETOOTH BASED HOME AUTOMATION
INTRODUCTION:
Wireless
technologies are becoming more popular around the world and the consumers
appreciate this wireless lifestyle which gives them relive of the well known
“cable chaos” that tends to grow under their desk. Now with the embedded
Bluetooth technology, digital devices form a network in which the appliances
and devices can communicate with each other. Today, home automation is one of
the major applications of Bluetooth technology. Operating over unlicensed, globally
available frequency of 2.4GHz, it can link digital devices within a range of
10m to 100m at the speed of up to 3Mbps depending on the Bluetooth device
class. With this capability of Bluetooth; we propose a home automation system
based on Bluetooth technology
There are few issues involved when designing a home automation
system. The system should be scalable so that new devices can easily be
integrated into it. It should provide a user- friendly interface on the host
side, so that the devices can be easily setup, monitored and controlled. This
interface should also provide some diagnostic services so that if there is any
problem with the system, it can be tracked down. Moreover the overall system
should be fast enough to realize the true power of wireless technology. Finally
the system should be cost effective in order to justify its application in home
automation.
In this paper we present a low cost secure cell phone based,
flexible home automation system. Appliances at home are connected to the Arduino
BT board. The communication between the cell phone and the Arduino BT board is
wireless. Additional devices can be connected into the system with little
modifications.
MATERIALS
AND METHODS:
MATERIALS:
1.
Arduino UNO R3 -
1
2.
HC-05 BT
module - 1
3.
12V
Relay - 4
4.
2N2222 Transistor -
4
5.
1N4007
Diode - 4
6.
Voltage
regulator(5V) - 1
7.
1kΩ
resistor - 4
8.
10kΩ
resistor - 1
9.
20kΩ
resistor - 1
COMPONENTS
DESCRIPTION:
1.Arduino UNO R3
·
The
Arduino Uno R3 is a microcontroller board based on a removable,
dual-inline-package (DIP) ATmega328 AVR microcontroller.
·
It has 20 digital input/output pins (of which
6 can be used as PWM outputs and 6 can be used as analog inputs), a 16 MHz
resonator, a USB connection, a power jack, an in-circuit system programming
(ICSP) header, and a reset button.
·
It contains everything needed to support the
microcontroller; simply connect it to a computer with a USB cable or power it with a AC-to-DC adaptor or battery to get started.
·
Programs
can be loaded on to it from the easy-to-use Arduino computer program. The
Arduino has an extensive support community, which makes it a very easy way to
get started working with embedded electronics.
·
It is the
latest revised version of Arduino
2.Bluetooth module(HC-05)
·
For the
communication between mobile phone and microcontroller Bluetooth module(HC-05)
is used.
·
HC-05 is
low power 1.8V operation and is easy to use with Bluetooth SPP.
·
Serial
port Bluetooth module have a Bluetooth 2.0+EDR (enhanced data rate), 3Mbps
modulation with complete 2.4GHZ radio transceiver and baseband.
·
Using
Bluetooth profile and android platform architecture different type of Bluetooth
applications can be developed.
3.
3.
12V Relay
· Relay is basically an electromagnetic switch
which can be turn on and off by an applying the voltage across its contacts.
· In this project used a 12V 4-channel relay.
4. 2N2222 Transistor
The 2N2222 is a common NPN bipolar
junction transistor (BJT) used for
general purpose low-power amplifying or switching applications. It is
designed for low to medium current, low power,
medium voltage, and can operate at moderately high
speeds.
METHOD:
Block
diagram:
Circuit
design:
The circuit design of Home Automation based on
Arduino and Bluetooth is very simple and is explained below.
The Bluetooth module has
4 – pins: VCC, TX, RX and GND. VCC and GND are connected to 5V and ground from
Arduino UNO. The Bluetooth module works on 3.3V and it has an on board 5V to
3.3V regulator.
The TX and RX pins of the Bluetooth
module must be connected to RX and TX pins of the Arduino. In Arduino UNO, we are defining pins 2
and 4 as RX and TX using software. Hence, TX of Bluetooth is connected to pin 4
of Arduino
But when connecting RX of
Bluetooth to TX of Arduino (or any microcontroller as a matter of fact), we
need to be careful as the pin can tolerate only 3.3V. But the voltage from TX
or Arduino will be 5V.
So, a voltage divider
network consisting of 10K and 20K resistors are used to reduce the voltage to
3.3V approximately.
Working:
When the power is turned on, the connection LED
on the Bluetooth module starts blinking. We need to start the “Bluetooth
Controller” app in our smartphone and get connected to the Bluetooth module. If
the pairing is successful, the LED becomes stable.
Now, in the app, we need to set different keys for different loads and
their corresponding value that must be transmitted when that key is pressed.
The following image shows a set of keys to control 4 loads and an additional
key to turn off all the loads.
Codings:
#include
<SoftwareSerial.h>
SoftwareSerial BT(0,
1); //TX, RX pins of arduino respetively
String command;
void setup()
{
BT.begin(9600);
Serial.begin(9600);
pinMode(2, OUTPUT);
pinMode(3, OUTPUT);
pinMode(4, OUTPUT);
pinMode(5,OUTPUT);
}
void loop() {
while (BT.available()){ //Check if there is an available byte to read
delay(10); //Delay added to make thing stable
char c = BT.read(); //Conduct a serial read
command += c; //build the string.
}
if (command.length() > 0) {
Serial.println(command);
if(command == "light on") //this
command will be given as an input to switch on light1
{
digitalWrite(2, HIGH);
}
else if(command == "light off")
//this command will be given as an input to switch off light1 simillarly other
commands work
{
digitalWrite(2, LOW);
}
else if (command == "lamp on")
{
digitalWrite (3, HIGH);
}
else if ( command == "lamp off")
{
digitalWrite (3, LOW);
}
else if (command == "fan on")
{
digitalWrite (4, HIGH);
}
else if (command == "fan off")
{
digitalWrite (4, LOW);
}
else if (command == "open")
{
digitalWrite (4, HIGH);
}
else if (command == "lock")
{
digitalWrite (4, LOW);
}
else if (command == "all on")
//using this command you can switch on all devices
{
digitalWrite (2, HIGH);
digitalWrite (3, HIGH);
digitalWrite (4, HIGH);
}
else if (command == "off")//using
this command you can switch off all devices
{
digitalWrite (2, LOW);
digitalWrite (3, LOW);
digitalWrite (4, LOW);
}
command="";}}
//Reset the variable
nice
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Deletegood well done....
ReplyDeletethanks alot..
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